It is recognized that substantially minimizing back problems can be accomplished by correct support of the anterior convexity of the lower lumbar region of a person, particularly when that person is seated for substantial periods of time, such as riding in a vehicle. Discussion of this subject matter is found for example in U.S. Pat. No. 4,597,386 which relates to a lumbar support device, preferably portable. Efforts have been made to incorporate lumbar support into vehicle seating, for example U.S. Pat. No. 4,690,456 shows and describes an arrangement in which a pair of plates are hinged to each other near their top margins, and a pair of selectively inflatable air bags are placed between these plates, the whole being incorporated within the construction of a vehicle seat. The result, however, is merely to distort the upholstered seat back in a general way, without regard to the need for a specific orthotic contoured support. Similar seating supports incorporating flexible strips and a mechanical distortion of them are available for use in both household and automotive seating, of which an example is disclosed in U.S. Pat. No. 4,354,709.
Another consideration is cost and complexity of manufacture. Prior art devices are, in general, rather expensive to make and install, thus discouraging their adoption over a wide range of vehicle types and models. There is a need for an adjustable lumbar support device which is economical to manufacture, install and service, which is readily adjusted, preferably over a substantial range of motion, to the unique lower back geometry of the person using the seating, and which will conform temporarily to twisting motions or the like as the user maneuvers his/her torso while seated against the support device.